The cost of reinforcement: selection on flower color in allopatric populations of Phlox drummondii.

Published

Journal Article

Reinforcement is the process by which increased reproductive isolation between incipient species evolves due to selection against maladaptive hybrids or costly hybrid mating. Reinforcement is predicted to create a pattern of greater prezygotic reproductive isolation in regions where the two species co-occur, sympatry, than in allopatry. Although most research on reinforcement focuses on understanding the evolutionary forces acting in sympatry, here we consider what prevents the alleles conferring greater reproductive isolation from spreading into allopatry. We investigate flower color divergence in the wildflower Phlox drummondii, which is caused by reinforcement in the regions sympatric with its congener Phlox cuspidata. Specifically, we performed common garden field experiments and pollinator observations to estimate selection acting on flower color variation in allopatry. We combine our estimates of maternal and paternal fitness using simulations and predict how flower color alleles migrating from sympatry will evolve in allopatry. Our results suggest that strong pollinator preference for the ancestral flower color in allopatry can maintain divergence between allopatric and sympatric populations.

Full Text

Duke Authors

Cited Authors

  • Hopkins, R; Rausher, MD

Published Date

  • May 2014

Published In

Volume / Issue

  • 183 / 5

Start / End Page

  • 693 - 710

PubMed ID

  • 24739201

Pubmed Central ID

  • 24739201

Electronic International Standard Serial Number (EISSN)

  • 1537-5323

International Standard Serial Number (ISSN)

  • 0003-0147

Digital Object Identifier (DOI)

  • 10.1086/675495

Language

  • eng